For many years, it has been known in the art that bowling balls having an inner core with a different density from the coverstock can be designed with certain beneficial inertial and other characteristics such as top weight and pin distance. Also having a core formed from a different material than the cover provides for the manufacture of a more economical bowling ball because the materials used for the cover of bowling balls are typically more expensive than the core material. It has been further known that bowling balls having multi-density core portions encapsulated within cover stock can provide additional benefits to the design of the inertial and other characteristics of bowling balls.
The downside to forming such bowling balls is that, until now, the core portions of such bowling balls had to be formed in a separate molding process, requiring additional equipment and labor. Once such core portions have been produced, they are placed into work-in-process (“WIP”) inventory, thereby increasing the working capital cost of the manufacturer. When the pre-molded core portions are used, they must first be fixtured and provided with bores before being placed on one or more locating pins in the mold used to form the bowling ball around the core portion(s).
The object of this invention is, therefore, to provide a bowling ball having one or more distinct core portions surrounded by a cover that can be formed in a continuous manufacturing process by incorporating one or more sacrificial mold cores into the bowling ball.